1. Technical Field
The present invention generally relates to characterization of network communications devices in a network and in particular to determining a network communications device type (switch vs. router). Still more particularly, the present invention relates to employing a neural network to determine a network communications device type from packet forwarding measurements.
2. Description of the Related Art
Computer networks are essential features of contemporary computing, providing the framework for exchange of data and execution of distributed applications, either through client-server interaction such as HyperText Transmission Protocol clients and servers or collaborative operation such as failover redundancy in highly available networks. In contemporary networking environments, most customers have a need to control the use of existing bandwidth so that network management traffic is not competing with the business traffic.
In order to minimize the potential negative impact of the management environment on the network infrastructure and performance, it is crucial that the management environment have information available regarding the underlying network topology. Through the utilization of such data, intelligent decisions may be made relevant to the design, implementation, and use of the management environment. In the network management field, there exists a strong need to have information regarding the physical network topology which is as accurate and detailed as possible to perform management tasks. For example, the process of distributing software to hundreds of workstations cannot be performed efficiently without an understanding of the physical topology.
Contemporary network communication devices are of two main types: networking devices that connect shared media (routers) and networking devices which connect dedicated media (switches). A mix of routing and switching network communication devices is not unusual, particularly in local area network (LAN) environments. Because the different manners in which these devices operate may have a dramatic impact on the performance of a management application, knowledge of the type of network communications device involved in performing the task is critical. Performance of communications between two nodes connected by a router is dependent on the existence and degree of traffic between other nodes through the router, while switch performance is essentially independent of traffic through the switch not involving the two nodes of interest.
Determining the underlying physical topology of a network is a non-trivial problem when the management application does not have access to the internal information (management information base or xe2x80x9cMIBxe2x80x9d) of the network communication devices (as where the vendor-specific information is kept private or proprietary). Today most networking environments utilize not only private paths but also xe2x80x9cpublicxe2x80x9d paths such as portions of the Internet, for which the internal information of network communications devices are kept private or privileged for security purposes. While a network management application may have access to the internal information of network communication devices belonging to the enterprise running the network management application, it generally will not have access to such information for devices belonging to other enterprises.
It would be desirable, therefore, to be able to determine the type (switch vs. router) of a network communications device without relying on internal information from the network communications device. It would further be advantageous to be able to make the determination of the type of a network communications device quickly and utilizing as little computing resources as possible.
It is therefore one object of the present invention to provide an improved method, system, and computer program product for characterization of networking communications devices in a network.
It is another object of the present invention to provide an improved method, system, and computer program product for determining a network communications device type (switch vs. router).
It is yet another object of the present invention to employ a neural network to determine a network communications device type from packet forwarding measurements.
The foregoing objects are achieved as is now described. To determine a network communications device type (switch or router) without reference to internal information within the network communications device, two packets having preselected, differing sizes (e.g., 64 bytes and 1500 bytes) are sequentially transmitted from one network node to another through the network communications device. The difference between the transmission start times for the two packets, determined by time references set up based on internal data processing system high resolution counters and placed in the IP packet payload, and the difference between the receipt stop timesxe2x80x94that is, when the last portions of the two packets are receivedxe2x80x94are compared. If the two differences are substantially the same, the network communications device is classified as a switch. If the two differences are unequal by an appreciable amount, the network communications device is classified as a router. Classification may optionally be performed by a neural network trained with the expect relative relationship between the transmission start times difference and the receipt stop times difference for the preselected packet sizes when transmitted through switches and routers.
The above as well as additional objectives, features, and advantages of the present invention will become apparent in the following detailed written description.